Darifenacin for the treatment of overactive bladder.

Overactive bladder is a debilitating disorder affecting 16.5% of adults and increasing in prevalence with age. Symptoms, including urgency, urge incontinence and frequency can result from detrusor overactivity with contraction of the bladder mediated primarily by activation of muscarinic M(3) receptors. Antimuscarinic agents are therefore an important approach to treating overactive bladder, but a lack of M(3) receptor subtype selectivity with these agents can generate a range of side effects that limits their effectiveness. This review describes an alternative approach to treating overactive bladder using the selective muscarinic M(3) receptor antagonist darifenacin. The M(3) receptor selectivity of darifenacin improves the symptoms of overactive bladder while reducing the potential for deleterious effects of non-M(3) muscarinic receptor antagonism in the brain or heart. The pharmacology and pharmacokinetics of darifenacin are summarized, and the its clinical efficacy and demonstrated safety profile are described.